1. Field of the Invention
The present invention relates to a method for manufacturing a rubber basketball, more particularly, to a method for manufacturing a rubber basketball containing a relatively rough surface capable of preventing the basketball from sliding.
2. Description of Related Art
With reference to FIG. 14, the conventional basketball includes a bladder (90) made of rubber, a wrapped layer (91) covering the outer surface of the bladder (90), an outer cover (92) covering the wrapped layer (91) and having some protrusions (93) and depressions (94) defined on the surface.
However, the conventional basketball has some difficulties. The depressions (94) defined on the outer cover (92) are too shallow to provide an effect on the contour of the outer cover (92) surface or to make a three-dimensioned basketball with an aesthetic appearance.
Another shortcoming found in the conventional basketball is that the depth of each depression (94) is relatively shallow so that it is not easy for the players who are playing with the conventional basketball to grasp it in their hands, and the conventional basketball intends to slide from the hands of players.
Therefore, there is still a need to resolve the above-mentioned difficulty and shortcoming.
The objective in accordance with the present invention is to provide a method for manufacturing a rubber basketball having a relatively rough surface capable of preventing the basketball from sliding out of the hands of the players.
To achieve the objective, the method of manufacturing a basketball in accordance with the present invention comprises:
(a) supplying a sheet of rubber material in a suitable shape and size;
(b) folding, compressing and cutting the rubber material to make the rubber material into a bladder;
(c) mounting a valve in the bladder;
(d) inflating the bladder with air and curing the bladder at a temperature from 130xc2x0 C. to 150xc2x0 C. for a period of time of about 5 minutes;
(e) wrapping at least one thread on the inflated bladder by a wrapping machine to form a wrapped layer with a suitable thickness and to pattern the bladder;
(f) bonding relatively large multiple rubber sheets, one adjacent to another, to the surface of the wrapped layer by a semi-automatic bonding machine;
(g) making a groove between any two of the adjacent rubber sheets;
(h) bonding a strip having a thinner and narrower size than the relatively large multiple rubber sheets at each junction of adjacent rubber sheets; and
(i) heating and curing the relatively large multiple rubber sheets together with the strips at a temperature from 130xc2x0 C. to 150xc2x0 C. for about 5 minutes in a mold having multiple protruding ribs defined therein to make a basketball, whereby the basketball possesses multiple, relatively concave depressions having two slanting walls defined therein.
Other objectives, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.